bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/internal/provisional/p2/metadata/MetadataFactory.java - equinox/rt.equinox.p2 - Git at Google

 /*******************************************************************************
  * Copyright (c) 2007, 2009 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Genuitec, LLC
  *		EclipseSource - ongoing development
  *******************************************************************************/
 package org.eclipse.equinox.internal.provisional.p2.metadata;

 import org.eclipse.equinox.p2.metadata.ICopyright;

 import java.net.URI;
 import java.util.*;
 import java.util.Map.Entry;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.equinox.internal.p2.metadata.*;
 import org.eclipse.equinox.p2.metadata.*;
 import org.eclipse.equinox.p2.metadata.query.IQuery;

 /**
  * A factory class for instantiating various p2 metadata objects.
  */
 public class MetadataFactory {
 	/**
 	 * A description containing information about an installable unit. Once created,
 	 * installable units are immutable. This description class allows a client to build
 	 * up the state for an installable unit incrementally, and then finally product
 	 * the resulting immutable unit.
 	 */
 	public static class InstallableUnitDescription {
 		public static final String PROP_TYPE_GROUP = "org.eclipse.equinox.p2.type.group"; //$NON-NLS-1$

 		protected InstallableUnit unit;

 		/**
 		 * A property key (value <code>"org.eclipse.equinox.p2.type.patch"</code>) for a
 		 * boolean property indicating that an installable unit is a group.
 		 *
 		 */
 		public static final String PROP_TYPE_PATCH = "org.eclipse.equinox.p2.type.patch"; //$NON-NLS-1$

 		/**
 		 * A property key (value <code>"org.eclipse.equinox.p2.type.fragment"</code>) for a
 		 * boolean property indicating that an installable unit is a fragment.
 		 *
 		 */
 		public static final String PROP_TYPE_FRAGMENT = "org.eclipse.equinox.p2.type.fragment"; //$NON-NLS-1$

 		/**
 		 * A property key (value <code>"org.eclipse.equinox.p2.type.category"</code>) for a
 		 * boolean property indicating that an installable unit is a category.
 		 *
 		 */
 		public static final String PROP_TYPE_CATEGORY = "org.eclipse.equinox.p2.type.category"; //$NON-NLS-1$

 		public InstallableUnitDescription() {
 			super();
 		}

 		public void addProvidedCapabilities(Collection additional) {
 			if (additional == null || additional.size() == 0)
 				return;
 			IProvidedCapability[] current = unit().getProvidedCapabilities();
 			IProvidedCapability[] result = new IProvidedCapability[additional.size() + current.length];
 			System.arraycopy(current, 0, result, 0, current.length);
 			int j = current.length;
 			for (Iterator i = additional.iterator(); i.hasNext();)
 				result[j++] = (IProvidedCapability) i.next();
 			unit().setCapabilities(result);
 		}

 		public void addRequiredCapabilities(Collection additional) {
 			if (additional == null || additional.size() == 0)
 				return;
 			IRequirement[] current = unit().getRequiredCapabilities();
 			IRequirement[] result = new IRequirement[additional.size() + current.length];
 			System.arraycopy(current, 0, result, 0, current.length);
 			int j = current.length;
 			for (Iterator i = additional.iterator(); i.hasNext();)
 				result[j++] = (IRequirement) i.next();
 			unit().setRequiredCapabilities(result);
 		}

 		public void addTouchpointData(ITouchpointData data) {
 			Assert.isNotNull(data);
 			unit().addTouchpointData(data);
 		}

 		public String getId() {
 			return unit().getId();
 		}

 		public IProvidedCapability[] getProvidedCapabilities() {
 			return unit().getProvidedCapabilities();
 		}

 		public IRequirement[] getRequiredCapabilities() {
 			return unit().getRequiredCapabilities();
 		}

 		public IRequirement[] getMetaRequiredCapabilities() {
 			return unit().getMetaRequiredCapabilities();
 		}

 		/**
 		 * Returns the current touchpoint data on this installable unit description. The
 		 * touchpoint data may change if further data is added to the description.
 		 *
 		 * @return The current touchpoint data on this description
 		 */
 		public ITouchpointData[] getTouchpointData() {
 			return unit().getTouchpointData();

 		}

 		public Version getVersion() {
 			return unit().getVersion();
 		}

 		public void setArtifacts(IArtifactKey[] value) {
 			unit().setArtifacts(value);
 		}

 		public void setCapabilities(IProvidedCapability[] exportedCapabilities) {
 			unit().setCapabilities(exportedCapabilities);
 		}

 		public void setCopyright(ICopyright copyright) {
 			unit().setCopyright(copyright);
 		}

 		public void setFilter(String filter) {
 			unit().setFilter(filter);
 		}

 		public void setId(String id) {
 			unit().setId(id);
 		}

 		public void setLicenses(ILicense[] licenses) {
 			unit().setLicenses(licenses);
 		}

 		public void setProperty(String key, String value) {
 			unit().setProperty(key, value);
 		}

 		public void setRequiredCapabilities(IRequirement[] requirements) {
 			unit().setRequiredCapabilities(requirements);
 		}

 		public void setMetaRequiredCapabilities(IRequirement[] metaRequirements) {
 			unit().setMetaRequiredCapabilities(metaRequirements);
 		}

 		public void setSingleton(boolean singleton) {
 			unit().setSingleton(singleton);
 		}

 		public void setTouchpointType(ITouchpointType type) {
 			unit().setTouchpointType(type);
 		}

 		public void setUpdateDescriptor(IUpdateDescriptor updateInfo) {
 			unit().setUpdateDescriptor(updateInfo);
 		}

 		public void setVersion(Version newVersion) {
 			unit().setVersion(newVersion);
 		}

 		InstallableUnit unit() {
 			if (unit == null) {
 				unit = new InstallableUnit();
 				unit.setArtifacts(new IArtifactKey[0]);
 			}
 			return unit;
 		}

 		IInstallableUnit unitCreate() {
 			IInstallableUnit result = unit();
 			this.unit = null;
 			return result;
 		}
 	}

 	public static class InstallableUnitFragmentDescription extends InstallableUnitDescription {
 		public InstallableUnitFragmentDescription() {
 			super();
 			setProperty(InstallableUnitDescription.PROP_TYPE_FRAGMENT, Boolean.TRUE.toString());
 		}

 		public void setHost(IRequirement[] hostRequirements) {
 			((InstallableUnitFragment) unit()).setHost(hostRequirements);
 		}

 		InstallableUnit unit() {
 			if (unit == null)
 				unit = new InstallableUnitFragment();
 			return unit;
 		}
 	}

 	public static class InstallableUnitPatchDescription extends InstallableUnitDescription {

 		public InstallableUnitPatchDescription() {
 			super();
 			setProperty(InstallableUnitDescription.PROP_TYPE_PATCH, Boolean.TRUE.toString());
 		}

 		public void setApplicabilityScope(IRequirement[][] applyTo) {
 			if (applyTo == null)
 				throw new IllegalArgumentException("A patch scope can not be null"); //$NON-NLS-1$
 			((InstallableUnitPatch) unit()).setApplicabilityScope(applyTo);
 		}

 		public void setLifeCycle(IRequirement lifeCycle) {
 			((InstallableUnitPatch) unit()).setLifeCycle(lifeCycle);
 		}

 		public void setRequirementChanges(IRequirementChange[] changes) {
 			((InstallableUnitPatch) unit()).setRequirementsChange(changes);
 		}

 		InstallableUnit unit() {
 			if (unit == null) {
 				unit = new InstallableUnitPatch();
 				((InstallableUnitPatch) unit()).setApplicabilityScope(new IRequirement[0][0]);
 			}
 			return unit;
 		}
 	}

 	/**
 	 * Singleton touchpoint data for a touchpoint with no instructions.
 	 */
 	private static final ITouchpointData EMPTY_TOUCHPOINT_DATA = new TouchpointData(Collections.EMPTY_MAP);

 	private static ITouchpointType[] typeCache = new ITouchpointType[5];

 	private static int typeCacheOffset;

 	/**
 	 * Returns an {@link IInstallableUnit} based on the given
 	 * description.  Once the installable unit has been created, the information is
 	 * discarded from the description object.
 	 *
 	 * @param description The description of the unit to create
 	 * @return The created installable unit
 	 */
 	public static IInstallableUnit createInstallableUnit(InstallableUnitDescription description) {
 		Assert.isNotNull(description);
 		return description.unitCreate();
 	}

 	/**
 	 * Returns an {@link IInstallableUnitFragment} based on the given
 	 * description.  Once the fragment has been created, the information is
 	 * discarded from the description object.
 	 *
 	 * @param description The description of the unit to create
 	 * @return The created installable unit fragment
 	 */
 	public static IInstallableUnitFragment createInstallableUnitFragment(InstallableUnitFragmentDescription description) {
 		Assert.isNotNull(description);
 		return (IInstallableUnitFragment) description.unitCreate();
 	}

 	/**
 	 * Returns an {@link IInstallableUnitPatch} based on the given
 	 * description.  Once the patch installable unit has been created, the information is
 	 * discarded from the description object.
 	 *
 	 * @param description The description of the unit to create
 	 * @return The created installable unit patch
 	 */
 	public static IInstallableUnitPatch createInstallableUnitPatch(InstallableUnitPatchDescription description) {
 		Assert.isNotNull(description);
 		return (IInstallableUnitPatch) description.unitCreate();
 	}

 	/**
 	 * Returns a {@link IProvidedCapability} with the given values.
 	 *
 	 * @param namespace The capability namespace
 	 * @param name The capability name
 	 * @param version The capability version
 	 */
 	public static IProvidedCapability createProvidedCapability(String namespace, String name, Version version) {
 		return new ProvidedCapability(namespace, name, version);
 	}

 	/**
 	 * Returns a {@link IRequirement} with the given values.
 	 *
 	 * @param namespace The capability namespace
 	 * @param name The required capability name
 	 * @param range The range of versions that are required, or <code>null</code>
 	 * to indicate that any version will do.
 	 * @param filter The filter used to evaluate whether this capability is applicable in the
 	 * current environment, or <code>null</code> to indicate this capability is always applicable
 	 * @param optional <code>true</code> if this required capability is optional,
 	 * and <code>false</code> otherwise.
 	 * @param multiple <code>true</code> if this capability can be satisfied by multiple provided capabilities, or it requires exactly one match
 	 */
 	public static IRequiredCapability createRequiredCapability(String namespace, String name, VersionRange range, String filter, boolean optional, boolean multiple) {
 		return new RequiredCapability(namespace, name, range, filter, optional, multiple);
 	}

 	public static IRequirement createRequiredCapability(String namespace, String name, VersionRange range, IQuery filter, int minCard, int maxCard, boolean greedy) {
 		return new RequiredCapability(namespace, name, range, filter, minCard, maxCard, greedy);
 	}

 	public static IRequiredCapability createRequiredCapability(String namespace, String name, VersionRange range, String filter, boolean optional, boolean multiple, boolean greedy) {
 		return new RequiredCapability(namespace, name, range, filter, optional, multiple, greedy);
 	}

 	/**
 	 * Returns a new requirement change.
 	 * @param applyOn The source of the requirement change - the kind of requirement to apply the change to
 	 * @param newValue The result of the requirement change - the requirement to replace the source requirement with
 	 * @return a requirement change
 	 */
 	public static IRequirementChange createRequirementChange(IRequirement applyOn, IRequirement newValue) {
 		if ((applyOn == null || applyOn instanceof IRequiredCapability) && (newValue == null || newValue instanceof IRequiredCapability))
 			return new RequirementChange((IRequiredCapability) applyOn, (IRequiredCapability) newValue);
 		throw new IllegalArgumentException();
 	}

 	/**
 	 * Returns a new {@link ICopyright}.
 	 * @param location the location of a document containing the copyright notice, or <code>null</code>
 	 * @param body the copyright body, cannot be <code>null</code>
 	 * @throws IllegalArgumentException when the <code>body</code> is <code>null</code>
 	 */
 	public static ICopyright createCopyright(URI location, String body) {
 		return new Copyright(location, body);
 	}

 	/**
 	 * Return a new {@link ILicense}
 	 * The body should contain either the full text of the license or an summary for a license
 	 * fully specified in the given location.
 	 *
 	 * @param location the location of a document containing the full license, or <code>null</code>
 	 * @param body the license body, cannot be <code>null</code>
 	 * @throws IllegalArgumentException when the <code>body</code> is <code>null</code>
 	 */
 	public static ILicense createLicense(URI location, String body) {
 		return new License(location, body);
 	}

 	/**
 	 * Returns an {@link IInstallableUnit} that represents the given
 	 * unit bound to the given fragments.
 	 *
 	 * @see IInstallableUnit#isResolved()
 	 * @param unit The unit to be bound
 	 * @param fragments The fragments to be bound
 	 * @return A resolved installable unit
 	 */
 	public static IInstallableUnit createResolvedInstallableUnit(IInstallableUnit unit, IInstallableUnitFragment[] fragments) {
 		if (unit.isResolved())
 			return unit;
 		Assert.isNotNull(unit);
 		Assert.isNotNull(fragments);
 		return new ResolvedInstallableUnit(unit, fragments);

 	}

 	/**
 	 * Returns an instance of {@link ITouchpointData} with the given instructions.
 	 *
 	 * @param instructions The instructions for the touchpoint data.
 	 * @return The created touchpoint data
 	 */
 	public static ITouchpointData createTouchpointData(Map instructions) {
 		Assert.isNotNull(instructions);
 		//copy the map to protect against subsequent change by caller
 		if (instructions.isEmpty())
 			return EMPTY_TOUCHPOINT_DATA;

 		Map result = new LinkedHashMap(instructions.size());
 		for (Iterator iterator = instructions.entrySet().iterator(); iterator.hasNext();) {
 			Entry entry = (Entry) iterator.next();
 			Object value = entry.getValue();
 			if (value == null || value instanceof String)
 				value = createTouchpointInstruction((String) value, null);

 			result.put(entry.getKey(), value);
 		}
 		return new TouchpointData(result);
 	}

 	/**
 	 * Merge the given touchpoint instructions with a pre-existing touchpoint data
 	 * @param initial - the initial ITouchpointData
 	 * @param incomingInstructions - Map of ITouchpointInstructions to merge into the initial touchpoint data
 	 * @return the merged ITouchpointData
 	 */
 	public static ITouchpointData mergeTouchpointData(ITouchpointData initial, Map incomingInstructions) {
 		if (incomingInstructions == null || incomingInstructions.size() == 0)
 			return initial;

 		Map resultInstructions = new HashMap(initial.getInstructions());
 		for (Iterator iterator = incomingInstructions.keySet().iterator(); iterator.hasNext();) {
 			String key = (String) iterator.next();
 			Object incoming = incomingInstructions.get(key);
 			ITouchpointInstruction instruction = (incoming instanceof String) ? createTouchpointInstruction((String) incoming, null) : (ITouchpointInstruction) incoming;
 			ITouchpointInstruction existingInstruction = (ITouchpointInstruction) resultInstructions.get(key);

 			if (existingInstruction != null) {
 				String body = existingInstruction.getBody();
 				if (body == null || body.length() == 0)
 					body = instruction.getBody();
 				else if (instruction.getBody() != null) {
 					if (!body.endsWith(";")) //$NON-NLS-1$
 						body += ';';
 					body += instruction.getBody();
 				}

 				String importAttribute = existingInstruction.getImportAttribute();
 				if (importAttribute == null || importAttribute.length() == 0)
 					importAttribute = instruction.getImportAttribute();
 				else if (instruction.getImportAttribute() != null) {
 					if (!importAttribute.endsWith(",")) //$NON-NLS-1$
 						importAttribute += ',';
 					importAttribute += instruction.getBody();
 				}
 				instruction = createTouchpointInstruction(body, importAttribute);
 			}
 			resultInstructions.put(key, instruction);
 		}
 		return createTouchpointData(resultInstructions);
 	}

 	public static ITouchpointInstruction createTouchpointInstruction(String body, String importAttribute) {
 		return new TouchpointInstruction(body, importAttribute);
 	}

 	/**
 	 * Returns a {@link TouchpointType} with the given id and version.
 	 *
 	 * @param id The touchpoint id
 	 * @param version The touchpoint version
 	 * @return A touchpoint type instance with the given id and version
 	 */
 	public static ITouchpointType createTouchpointType(String id, Version version) {
 		Assert.isNotNull(id);
 		Assert.isNotNull(version);

 		if (id.equals(ITouchpointType.NONE.getId()) && version.equals(ITouchpointType.NONE.getVersion()))
 			return ITouchpointType.NONE;

 		synchronized (typeCache) {
 			ITouchpointType result = getCachedTouchpointType(id, version);
 			if (result != null)
 				return result;
 			result = new TouchpointType(id, version);
 			putCachedTouchpointType(result);
 			return result;
 		}
 	}

 	public static IUpdateDescriptor createUpdateDescriptor(String id, VersionRange range, int severity, String description) {
 		return new UpdateDescriptor(id, range, severity, description);
 	}

 	private static ITouchpointType getCachedTouchpointType(String id, Version version) {
 		for (int i = 0; i < typeCache.length; i++) {
 			if (typeCache[i] != null && typeCache[i].getId().equals(id) && typeCache[i].getVersion().equals(version))
 				return typeCache[i];
 		}
 		return null;
 	}

 	private static void putCachedTouchpointType(ITouchpointType result) {
 		//simple rotating buffer
 		typeCache[typeCacheOffset] = result;
 		typeCacheOffset = (typeCacheOffset + 1) % typeCache.length;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2007, 2009 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Genuitec, LLC
	* EclipseSource - ongoing development
	*******************************************************************************/
	package org.eclipse.equinox.internal.provisional.p2.metadata;

	import org.eclipse.equinox.p2.metadata.ICopyright;

	import java.net.URI;
	import java.util.*;
	import java.util.Map.Entry;
	import org.eclipse.core.runtime.Assert;
	import org.eclipse.equinox.internal.p2.metadata.*;
	import org.eclipse.equinox.p2.metadata.*;
	import org.eclipse.equinox.p2.metadata.query.IQuery;

	/**
	* A factory class for instantiating various p2 metadata objects.
	*/
	public class MetadataFactory {
	/**
	* A description containing information about an installable unit. Once created,
	* installable units are immutable. This description class allows a client to build
	* up the state for an installable unit incrementally, and then finally product
	* the resulting immutable unit.
	*/
	public static class InstallableUnitDescription {
	public static final String PROP_TYPE_GROUP = "org.eclipse.equinox.p2.type.group"; //$NON-NLS-1$

	protected InstallableUnit unit;

	/**
	* A property key (value <code>"org.eclipse.equinox.p2.type.patch"</code>) for a
	* boolean property indicating that an installable unit is a group.
	*
	*/
	public static final String PROP_TYPE_PATCH = "org.eclipse.equinox.p2.type.patch"; //$NON-NLS-1$

	/**
	* A property key (value <code>"org.eclipse.equinox.p2.type.fragment"</code>) for a
	* boolean property indicating that an installable unit is a fragment.
	*
	*/
	public static final String PROP_TYPE_FRAGMENT = "org.eclipse.equinox.p2.type.fragment"; //$NON-NLS-1$

	/**
	* A property key (value <code>"org.eclipse.equinox.p2.type.category"</code>) for a
	* boolean property indicating that an installable unit is a category.
	*
	*/
	public static final String PROP_TYPE_CATEGORY = "org.eclipse.equinox.p2.type.category"; //$NON-NLS-1$

	public InstallableUnitDescription() {
	super();
	}

	public void addProvidedCapabilities(Collection additional) {
	if (additional == null \|\| additional.size() == 0)
	return;
	IProvidedCapability[] current = unit().getProvidedCapabilities();
	IProvidedCapability[] result = new IProvidedCapability[additional.size() + current.length];
	System.arraycopy(current, 0, result, 0, current.length);
	int j = current.length;
	for (Iterator i = additional.iterator(); i.hasNext();)
	result[j++] = (IProvidedCapability) i.next();
	unit().setCapabilities(result);
	}

	public void addRequiredCapabilities(Collection additional) {
	if (additional == null \|\| additional.size() == 0)
	return;
	IRequirement[] current = unit().getRequiredCapabilities();
	IRequirement[] result = new IRequirement[additional.size() + current.length];
	System.arraycopy(current, 0, result, 0, current.length);
	int j = current.length;
	for (Iterator i = additional.iterator(); i.hasNext();)
	result[j++] = (IRequirement) i.next();
	unit().setRequiredCapabilities(result);
	}

	public void addTouchpointData(ITouchpointData data) {
	Assert.isNotNull(data);
	unit().addTouchpointData(data);
	}

	public String getId() {
	return unit().getId();
	}

	public IProvidedCapability[] getProvidedCapabilities() {
	return unit().getProvidedCapabilities();
	}

	public IRequirement[] getRequiredCapabilities() {
	return unit().getRequiredCapabilities();
	}

	public IRequirement[] getMetaRequiredCapabilities() {
	return unit().getMetaRequiredCapabilities();
	}

	/**
	* Returns the current touchpoint data on this installable unit description. The
	* touchpoint data may change if further data is added to the description.
	*
	* @return The current touchpoint data on this description
	*/
	public ITouchpointData[] getTouchpointData() {
	return unit().getTouchpointData();

	}

	public Version getVersion() {
	return unit().getVersion();
	}

	public void setArtifacts(IArtifactKey[] value) {
	unit().setArtifacts(value);
	}

	public void setCapabilities(IProvidedCapability[] exportedCapabilities) {
	unit().setCapabilities(exportedCapabilities);
	}

	public void setCopyright(ICopyright copyright) {
	unit().setCopyright(copyright);
	}

	public void setFilter(String filter) {
	unit().setFilter(filter);
	}

	public void setId(String id) {
	unit().setId(id);
	}

	public void setLicenses(ILicense[] licenses) {
	unit().setLicenses(licenses);
	}

	public void setProperty(String key, String value) {
	unit().setProperty(key, value);
	}

	public void setRequiredCapabilities(IRequirement[] requirements) {
	unit().setRequiredCapabilities(requirements);
	}

	public void setMetaRequiredCapabilities(IRequirement[] metaRequirements) {
	unit().setMetaRequiredCapabilities(metaRequirements);
	}

	public void setSingleton(boolean singleton) {
	unit().setSingleton(singleton);
	}

	public void setTouchpointType(ITouchpointType type) {
	unit().setTouchpointType(type);
	}

	public void setUpdateDescriptor(IUpdateDescriptor updateInfo) {
	unit().setUpdateDescriptor(updateInfo);
	}

	public void setVersion(Version newVersion) {
	unit().setVersion(newVersion);
	}

	InstallableUnit unit() {
	if (unit == null) {
	unit = new InstallableUnit();
	unit.setArtifacts(new IArtifactKey[0]);
	}
	return unit;
	}

	IInstallableUnit unitCreate() {
	IInstallableUnit result = unit();
	this.unit = null;
	return result;
	}
	}

	public static class InstallableUnitFragmentDescription extends InstallableUnitDescription {
	public InstallableUnitFragmentDescription() {
	super();
	setProperty(InstallableUnitDescription.PROP_TYPE_FRAGMENT, Boolean.TRUE.toString());
	}

	public void setHost(IRequirement[] hostRequirements) {
	((InstallableUnitFragment) unit()).setHost(hostRequirements);
	}

	InstallableUnit unit() {
	if (unit == null)
	unit = new InstallableUnitFragment();
	return unit;
	}
	}

	public static class InstallableUnitPatchDescription extends InstallableUnitDescription {

	public InstallableUnitPatchDescription() {
	super();
	setProperty(InstallableUnitDescription.PROP_TYPE_PATCH, Boolean.TRUE.toString());
	}

	public void setApplicabilityScope(IRequirement[][] applyTo) {
	if (applyTo == null)
	throw new IllegalArgumentException("A patch scope can not be null"); //$NON-NLS-1$
	((InstallableUnitPatch) unit()).setApplicabilityScope(applyTo);
	}

	public void setLifeCycle(IRequirement lifeCycle) {
	((InstallableUnitPatch) unit()).setLifeCycle(lifeCycle);
	}

	public void setRequirementChanges(IRequirementChange[] changes) {
	((InstallableUnitPatch) unit()).setRequirementsChange(changes);
	}

	InstallableUnit unit() {
	if (unit == null) {
	unit = new InstallableUnitPatch();
	((InstallableUnitPatch) unit()).setApplicabilityScope(new IRequirement[0][0]);
	}
	return unit;
	}
	}

	/**
	* Singleton touchpoint data for a touchpoint with no instructions.
	*/
	private static final ITouchpointData EMPTY_TOUCHPOINT_DATA = new TouchpointData(Collections.EMPTY_MAP);

	private static ITouchpointType[] typeCache = new ITouchpointType[5];

	private static int typeCacheOffset;

	/**
	* Returns an {@link IInstallableUnit} based on the given
	* description. Once the installable unit has been created, the information is
	* discarded from the description object.
	*
	* @param description The description of the unit to create
	* @return The created installable unit
	*/
	public static IInstallableUnit createInstallableUnit(InstallableUnitDescription description) {
	Assert.isNotNull(description);
	return description.unitCreate();
	}

	/**
	* Returns an {@link IInstallableUnitFragment} based on the given
	* description. Once the fragment has been created, the information is
	* discarded from the description object.
	*
	* @param description The description of the unit to create
	* @return The created installable unit fragment
	*/
	public static IInstallableUnitFragment createInstallableUnitFragment(InstallableUnitFragmentDescription description) {
	Assert.isNotNull(description);
	return (IInstallableUnitFragment) description.unitCreate();
	}

	/**
	* Returns an {@link IInstallableUnitPatch} based on the given
	* description. Once the patch installable unit has been created, the information is
	* discarded from the description object.
	*
	* @param description The description of the unit to create
	* @return The created installable unit patch
	*/
	public static IInstallableUnitPatch createInstallableUnitPatch(InstallableUnitPatchDescription description) {
	Assert.isNotNull(description);
	return (IInstallableUnitPatch) description.unitCreate();
	}

	/**
	* Returns a {@link IProvidedCapability} with the given values.
	*
	* @param namespace The capability namespace
	* @param name The capability name
	* @param version The capability version
	*/
	public static IProvidedCapability createProvidedCapability(String namespace, String name, Version version) {
	return new ProvidedCapability(namespace, name, version);
	}

	/**
	* Returns a {@link IRequirement} with the given values.
	*
	* @param namespace The capability namespace
	* @param name The required capability name
	* @param range The range of versions that are required, or <code>null</code>
	* to indicate that any version will do.
	* @param filter The filter used to evaluate whether this capability is applicable in the
	* current environment, or <code>null</code> to indicate this capability is always applicable
	* @param optional <code>true</code> if this required capability is optional,
	* and <code>false</code> otherwise.
	* @param multiple <code>true</code> if this capability can be satisfied by multiple provided capabilities, or it requires exactly one match
	*/
	public static IRequiredCapability createRequiredCapability(String namespace, String name, VersionRange range, String filter, boolean optional, boolean multiple) {
	return new RequiredCapability(namespace, name, range, filter, optional, multiple);
	}

	public static IRequirement createRequiredCapability(String namespace, String name, VersionRange range, IQuery filter, int minCard, int maxCard, boolean greedy) {
	return new RequiredCapability(namespace, name, range, filter, minCard, maxCard, greedy);
	}

	public static IRequiredCapability createRequiredCapability(String namespace, String name, VersionRange range, String filter, boolean optional, boolean multiple, boolean greedy) {
	return new RequiredCapability(namespace, name, range, filter, optional, multiple, greedy);
	}

	/**
	* Returns a new requirement change.
	* @param applyOn The source of the requirement change - the kind of requirement to apply the change to
	* @param newValue The result of the requirement change - the requirement to replace the source requirement with
	* @return a requirement change
	*/
	public static IRequirementChange createRequirementChange(IRequirement applyOn, IRequirement newValue) {
	if ((applyOn == null \|\| applyOn instanceof IRequiredCapability) && (newValue == null \|\| newValue instanceof IRequiredCapability))
	return new RequirementChange((IRequiredCapability) applyOn, (IRequiredCapability) newValue);
	throw new IllegalArgumentException();
	}

	/**
	* Returns a new {@link ICopyright}.
	* @param location the location of a document containing the copyright notice, or <code>null</code>
	* @param body the copyright body, cannot be <code>null</code>
	* @throws IllegalArgumentException when the <code>body</code> is <code>null</code>
	*/
	public static ICopyright createCopyright(URI location, String body) {
	return new Copyright(location, body);
	}

	/**
	* Return a new {@link ILicense}
	* The body should contain either the full text of the license or an summary for a license
	* fully specified in the given location.
	*
	* @param location the location of a document containing the full license, or <code>null</code>
	* @param body the license body, cannot be <code>null</code>
	* @throws IllegalArgumentException when the <code>body</code> is <code>null</code>
	*/
	public static ILicense createLicense(URI location, String body) {
	return new License(location, body);
	}

	/**
	* Returns an {@link IInstallableUnit} that represents the given
	* unit bound to the given fragments.
	*
	* @see IInstallableUnit#isResolved()
	* @param unit The unit to be bound
	* @param fragments The fragments to be bound
	* @return A resolved installable unit
	*/
	public static IInstallableUnit createResolvedInstallableUnit(IInstallableUnit unit, IInstallableUnitFragment[] fragments) {
	if (unit.isResolved())
	return unit;
	Assert.isNotNull(unit);
	Assert.isNotNull(fragments);
	return new ResolvedInstallableUnit(unit, fragments);

	}

	/**
	* Returns an instance of {@link ITouchpointData} with the given instructions.
	*
	* @param instructions The instructions for the touchpoint data.
	* @return The created touchpoint data
	*/
	public static ITouchpointData createTouchpointData(Map instructions) {
	Assert.isNotNull(instructions);
	//copy the map to protect against subsequent change by caller
	if (instructions.isEmpty())
	return EMPTY_TOUCHPOINT_DATA;

	Map result = new LinkedHashMap(instructions.size());
	for (Iterator iterator = instructions.entrySet().iterator(); iterator.hasNext();) {
	Entry entry = (Entry) iterator.next();
	Object value = entry.getValue();
	if (value == null \|\| value instanceof String)
	value = createTouchpointInstruction((String) value, null);

	result.put(entry.getKey(), value);
	}
	return new TouchpointData(result);
	}

	/**
	* Merge the given touchpoint instructions with a pre-existing touchpoint data
	* @param initial - the initial ITouchpointData
	* @param incomingInstructions - Map of ITouchpointInstructions to merge into the initial touchpoint data
	* @return the merged ITouchpointData
	*/
	public static ITouchpointData mergeTouchpointData(ITouchpointData initial, Map incomingInstructions) {
	if (incomingInstructions == null \|\| incomingInstructions.size() == 0)
	return initial;

	Map resultInstructions = new HashMap(initial.getInstructions());
	for (Iterator iterator = incomingInstructions.keySet().iterator(); iterator.hasNext();) {
	String key = (String) iterator.next();
	Object incoming = incomingInstructions.get(key);
	ITouchpointInstruction instruction = (incoming instanceof String) ? createTouchpointInstruction((String) incoming, null) : (ITouchpointInstruction) incoming;
	ITouchpointInstruction existingInstruction = (ITouchpointInstruction) resultInstructions.get(key);

	if (existingInstruction != null) {
	String body = existingInstruction.getBody();
	if (body == null \|\| body.length() == 0)
	body = instruction.getBody();
	else if (instruction.getBody() != null) {
	if (!body.endsWith(";")) //$NON-NLS-1$
	body += ';';
	body += instruction.getBody();
	}

	String importAttribute = existingInstruction.getImportAttribute();
	if (importAttribute == null \|\| importAttribute.length() == 0)
	importAttribute = instruction.getImportAttribute();
	else if (instruction.getImportAttribute() != null) {
	if (!importAttribute.endsWith(",")) //$NON-NLS-1$
	importAttribute += ',';
	importAttribute += instruction.getBody();
	}
	instruction = createTouchpointInstruction(body, importAttribute);
	}
	resultInstructions.put(key, instruction);
	}
	return createTouchpointData(resultInstructions);
	}

	public static ITouchpointInstruction createTouchpointInstruction(String body, String importAttribute) {
	return new TouchpointInstruction(body, importAttribute);
	}

	/**
	* Returns a {@link TouchpointType} with the given id and version.
	*
	* @param id The touchpoint id
	* @param version The touchpoint version
	* @return A touchpoint type instance with the given id and version
	*/
	public static ITouchpointType createTouchpointType(String id, Version version) {
	Assert.isNotNull(id);
	Assert.isNotNull(version);

	if (id.equals(ITouchpointType.NONE.getId()) && version.equals(ITouchpointType.NONE.getVersion()))
	return ITouchpointType.NONE;

	synchronized (typeCache) {
	ITouchpointType result = getCachedTouchpointType(id, version);
	if (result != null)
	return result;
	result = new TouchpointType(id, version);
	putCachedTouchpointType(result);
	return result;
	}
	}

	public static IUpdateDescriptor createUpdateDescriptor(String id, VersionRange range, int severity, String description) {
	return new UpdateDescriptor(id, range, severity, description);
	}

	private static ITouchpointType getCachedTouchpointType(String id, Version version) {
	for (int i = 0; i < typeCache.length; i++) {
	if (typeCache[i] != null && typeCache[i].getId().equals(id) && typeCache[i].getVersion().equals(version))
	return typeCache[i];
	}
	return null;
	}

	private static void putCachedTouchpointType(ITouchpointType result) {
	//simple rotating buffer
	typeCache[typeCacheOffset] = result;
	typeCacheOffset = (typeCacheOffset + 1) % typeCache.length;
	}
	}